So I purchased an iMac today but I did it at our university's bookstore rather than through the Apple store because it was cheaper. As soon as I opened it up and turned on the computer, I saw a fine line on the lower right corner of the screen, which I couldn't wipe off. I didn't know what it was so I called up the store and they said I could bring it in for an exchange. When I brought the computer in, the bookstore people looked over the computer and agreed to give me an exchange. One of them brought out another iMac and while I was looking over the box, another employee pried open the glass encasement and took out the problem (it must have been a hair or something). Because there weren't any other problems with the computer (that I could see at the time anyway), I brought it back home. When I turned on the computer at home and examined it closely, I saw that there was a lot of dust under the screen because he had lifted off the glass. Should I ask for an exchange? Photography is a serious hobby of mine and I am overly sensitive about dead/stuck pixels on computers. What would you guys do if you were me? It annoyed me that the employee "fixed" my computer without asking or telling me because I knew that that would just lead to dust under the screen.